Air cooled transformer



March 29, 1932. H. B. KEATH AIR COOLED TRANSFORMER Filed April 18, 1931 Inventor ,I .5. KEATH Atty.,

Patented Mar. 29, 1932 UNITED STATES PATENT OFFICE HOWARD IB. KEATH, OF RICHMOND HEIGHTS, MISSOURI, ASSIG-NOR TO WAGNER ELEC--V TRIO CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION' 0F DELAWARE AIR COOLED TRANSFORMER Application filed April 18,

My invention relates to the cooling of electrical apparatus and has special reference to transformers which are enclosed in a liquid containing tank. Such tanks are generally made either with plain or corrugated surfaces with external radiating tubes connected to the top and bottom thereof to allow for a more rapid dissipation of heat from the liquid. The heated liquid, generally oil, rises to the top of the tank and passes into the upper part of the tubes and as the liquid dissipates its heat through the walls of the tubes into the surrounding air it will :dow downwardly through the tubes to the bottom of the tank. The radiating surface of the tubes generally is not large enough to dissipate the heat from the fluid as rapidly as desired and it is the practice to subject the surfaces of tubes to currents of air. One

of the objects of my invention is to provide an improved method of circulating air currents over the radiating tubes and tank to increase their radiating efficiency.

Another object of my invention is to subject the radiating tubes of a transformer tank to a maximum of cooling air by the use of a minimum amount of forced air.

Still another object of my invention is to produce an efficient cooling system for a transformer without increasing the over-all dimension of the liquid containing tank and the radiator tubes and one which can be readily placed on existing types of transformer tanks without in any way changing their construction.

Reference is now made to the drawings in which Figure 1 is a side view, partially in section, disclosing the invention applied to a transformer tank with external radiating tubes; and Figure 2 is a front view of one of the banks of radiating tubes showing how the air circulating means is attached.

The numeral 1 designates a rectangularshaped tank of suitable dimensions in which is placed a transformer 2 immersed in an insulating flL1id,-oil in this instance. The top of the tank is closed by a cover 3 which carries the electrical leads for the transformer winding. On opposite sides of the tank and spaced therefrom is a bank of radiating tubes 1931. Serial N0. 531,141.

t which consists of two rows of spaced apart elliptical-shaped tubes 5 terminating in headers 6 and 7 at the ends thereof. These headers are connected to the interior of the tank by means of tubes 8 having flanges 9 at one end for attachment to the wall of the tank by any suitable means. The heated oil in the tank circulates from the top of the tank to the bottom through the tubes 5 and is thereby cooled by the surrounding air. Other banks of tubes may be placed on the other sides of the tank if it is so desired.

To increase the efficiency of the radiating tubes it is desirable to subject their surfaces to a continuous current of cool air. This current of cool air serves the two-fold purpose of carrying the heated air away from the tubes and of bringing the cool air into contact with the tubes. It is also desirable to have these currents of air pass over the tubes at an acute angle thereto so as to assist the heated air about the tubes to rise.

In accordance with my invention I attach a blower to the bank of tubes below the lower header in such a way that a continuous blast or column of air will be directed vertically upward into the space between the tank and the tubes. This column of air in moving vertically upward causes currents of air to pass between and around the radiating tubes, as shown by the arrows in Figure l, and also along the wall of the tank, resulting in the wall and the entire radiating surface of the tubes being subjected at all times to moving air. Since the air from the blower and the currents of air passing over the tubes are always moving upwardly, the heat radiated by the tank and the tubes is rapidly moved away from the radiating surfaces.

Tests have shown that this method of cooling the tank and radiating tubes of a transformer is approximately fifty per cent more effective than where the air is blown only directly upon the radiating tubes at right angles thereto with no provision for carrying the heated air upwardly and away from the tubes.

The embodiment of my invention shown consists of an air conduit l() suspended from the bank of tubes by means of a strap 11 overlying the header member 7 between the rows Aian.

of tubes and connected by bolts 12 at its ends to brackets 13 fixed to the sides of the air conduit. The small end of the air conduit is formed in two outlet ports 14 and 15 so as to it around the connecting tube 8. Both of these outlets are curved and extend. Vertically slipwardly iinto I the Nlower part ,of the space between the wall of the tank and the bank of radiating tubes. In the main body ofthe -air conduit-10 isvplaced ablower com-- prising yanelectric motor 16and afan -17 the fan being adjacent the circular opening 18 in the end of the air conduit. One side of the air conduit is proyided with :a door-l9 Y for'inspection and repair of the motor and Yt it l-Sircessary to. .have two fansite :pro

Vide a '.suiicient continucms ,blast bf air ',throughtheoutlets 14 and l5, they maybe n placedginthe airconduit directly opposite the 1 outlets in amanner similar tothe mounting of the oneshown but with separatey openings ,18 therefor.

:Jlrom the foregoing description it is Aapi -fparentgthat Ihave produced rla Veryelicient means fior cooling a transformer tank which can easily and readily be attached toexist- VI-Iayi-ng fully described ymy inventiomwhat Y .I claim Vasnew and desire to secure byrLetters Patent ,of the United. States Ais v1. "The'combination of a fluid containing tank for artransformer, 2a tank Vof spaced ,apartLeXternal ,radiating tubes connected .to

thegtopmndibottom of the tankand spaced 4.

therefrom and through which the .fluidcir- ,culates, and means Jfor rdirectingacontinu- .ousxblast of airbetweenfthebank oftubes and the :tank andparallelto the tank, whereby :airfrom the surrounding bodyof .air willgbe tubes, .and means for, directing Vthe air from drawn between the tubes lat Aan Aacute angle thereto.

2. Ingcombinationwith aliquid containing tank for aitransformerhaving a bank of vertical radiatingtubes spaced `from each other andk fromth'e tank and through which the liquid circulates, of a y.blower beneath the the `blower ,vertically upward into the space abetweenthebankof tubes and the tank.

3. The combination with a t)fluid contain- Vi-nggtank having ap-lurality of external radiating tubes spaced from the tank an'dfrom `each other andlthrough which the fluid circulates, an air conduit extending into the IOWerpartof the space between the ltank and the tubes and positioned to vdischarge air in va direction parallel togthe tubes, and a'blower in said conduit.

vIn testimony whereof, I'hereunto afixmy signature, this 14th day of April, :1931.

Y -HowAnD ,.B. Kin-MH. 

